I need to deploy my custom firmware build to my Omega2S+ based devices, but since a new board will not have a wireless connection I need to use the ethernet connection also built into my board. So there is no reliance upon ipv4 address, this script finds the connected ipv6 device, uses scp to transfer the firmware to the device, then executes sysupgrade on the device.
Have you tried downloading the latest firmware to /tmp/ on the Omega and doing a sysupgrade /tmp/<firmware-image> manually?
If your Omega has network, you can pull the firmware from an ssh shell and perform the upgrade.
If your Omega doesn't have upstream connectivity, you can scp (or pscp on windows) the firwmare image downloaded to your workstation/laptop over to the Omega to perform a manual upgrade.